It is common prior practice to use a conventional, hand held knife, at the job site, to manually cut a conventional asphalt roofing shingle (such as a so-called "three-in-one" shingle) into one or more ridge shingles for placement at the peak or ridge, of a roof. Such practice requires two manual cuts, one after the other, to form each ridge shingle. Such practice tends to produce ridge shingles relatively slowly. Such hand knife cutting tends to be inaccurate and produce non-uniformily sized and shaped ridge shingles. Further, hand knife blades dull quickly and require frequent replacement or sharpening. Manually cutting shingles with a hand knife requires substantial manual force, and tires the user after cutting relatively few shingles. Such hand knife cutting risks injury to the knife user and to material adjacent the shingle being cut.
Accordingly, it is an object of this invention to provide an improved portable device for cutting conventional shingles into ridge shingles, while avoiding one or more of the above discussed disadvantages of the prior practice.